Bicycle with suspension

Abstract

A bicycle can include a suspension system with a shock absorber. The shock absorber can have a sag position which can be adjustable. Sag refers to the amount of movement experienced by the suspension under a static load, such as that of the weight of a rider. Methods and systems to set sag can include at least one valve in fluid communication with a gas chamber of the shock absorber. In some embodiments, the at least one valve can be used to automatically set the sag position based on an individual's weight and riding position.

What is claimed is: 
     
       1. A bicycle assembly comprising:
 a shock absorber comprising:
 a gas spring assembly having an interior surface; 
 a movable piston forming a seal with the interior surface and configured to move along the interior surface; 
 at least one valve for inflating and deflating the gas spring assembly with fluid; 
 at least one valve port configured to establish fluid communication between the gas spring assembly and the at least one valve; 
 wherein the gas spring assembly is divided by the piston into a first chamber and a second chamber, the first and second chambers configured to be determined at least in part by the position of the piston within the gas spring assembly, and the at least one valve port being positioned to communicate with the first chamber when in a given uncompressed position and communicate with the second chamber and not the first chamber when in a first compressed position. 
 
 
     
     
       2. The bicycle assembly of  claim 1 , wherein the gas spring assembly further comprises a bypass channel to allow fluid communication between the first and second chambers to thereby equalize the pressure in the spring assembly, 
     
     
       3. The bicycle assembly of  claim 2 , wherein the bypass channel comprises a groove along an interior surface of the gas chamber. 
     
     
       4. The bicycle assembly of  claim 1 , wherein the at least one valve port is in communication with both the first and the second chambers when in a second compressed position. 
     
     
       5. The bicycle assembly of  claim 1 , wherein the at least one valve port is along the interior surface of the gas chamber. 
     
     
       6. The bicycle assembly of  claim 1 , wherein the shock absorber further comprises a damping assembly, wherein the piston is positioned between the damping assembly and the gas spring assembly. 
     
     
       7. The bicycle assembly of  claim 1 , wherein the shock absorber comprises a rear shock absorber. 
     
     
       8. The bicycle assembly of  claim 1 , wherein the at least one valve comprises a Schrader or Presta valve. 
     
     
       9. The bicycle assembly of  claim 1 , wherein the at least one valve comprises two valves. 
     
     
       10. The bicycle assembly of  claim 1 , further comprising a main frame and a sub-frame, wherein the shock absorber is configured to regulate a relationship between the main frame and the sub-frame. 
     
     
       11. The bicycle assembly of  claim 10 , further comprising handle bars, operatively coupled to the main frame and two wheels, one wheel operatively coupled to the main frame and one wheel operatively coupled to the sub-frame. 
     
     
       12. A method of adjusting a bicycle suspension sag position comprising:
 inflating the gas spring assembly of the bicycle assembly of  claim 1  through the at least one valve to a pressure of at least 250 psi; 
 compressing the shock absorber by a person is sitting on the bicycle in a riding position; 
 deflating the gas spring assembly through the at least one valve while the person is sitting on the bicycle in the riding position until the piston passes the at least one valve port; and 
 closing the connection between the at least one valve and the first chamber. 
 
     
     
       13. The method of  claim 12 , further comprising shutting the at least one valve. 
     
     
       14. A bicycle assembly comprising:
 a shock absorber comprising:
 a gas spring assembly having an interior surface; 
 a movable piston forming a seal with the interior surface and configured to move along the interior surface; 
 at least one valve for inflating and deflating the gas spring assembly with fluid; 
 at least one valve port configured to establish fluid communication between the gas spring assembly and the at least one valve; 
 wherein the gas spring assembly is divided by the piston into a first chamber and a second chamber, the first and second chambers configured to be determined at least in part by the position of the piston within the gas spring assembly, and the at least one valve port being positioned to communicate with the first chamber and not the second chamber when in a given uncompressed position and communicate with the second chamber when in a given compressed position. 
 
 
     
     
       15. The bicycle assembly of  claim 1 , wherein the first chamber is a positive gas chamber. 
     
     
       16. The bicycle assembly of  claim 15 , wherein the second chamber is a negative gas chamber. 
     
     
       17. The bicycle assembly of  claim 1 , wherein the at least one valve for inflating and deflating the gas spring assembly is configured to deflate the gas spring assembly to the atmosphere. 
     
     
       18. The bicycle assembly of  claim 9 , wherein the first valve is in communication with the first chamber and the second valve is adjacent to the at least one valve port. 
     
     
       19. The bicycle assembly of  claim 1 , wherein the at least one valve is adjacent the at least one valve port and when open, the at least one valve vents the chamber to the atmosphere. 
     
     
       20. The method of  claim 12 , wherein deflating the gas spring assembly further comprises deflating the gas spring assembly through the at least one valve and to the atmosphere.